Android开发_Gson解析

1. //转换器
2. GsonBuilder builder = new GsonBuilder();
3. // 不转换没有 @Expose 注解的字段
4. builder.excludeFieldsWithoutExposeAnnotation();
5. Gson gson = builder.create();
6. //1、对象转string
7. Student stu = new Student();
8. );
9. stu.setStudentName("qqq");
10. String stuStr = gson.toJson(stu);
11. System.out.println(stuStr); //{"studentName":"qqq","studentId":333}
12. //2、string转对象
13. Student user2 = gson.fromJson(stuStr, Student.class);
14. System.out.println(user2);
15. String stuTemp = "{\"studentName\":\"qqq2\",\"studentId\":3335}";
16. Student user4 = gson.fromJson(stuTemp, Student.class);
17. System.out.println(user4);
18. //3、对象List转string
19. List<Student> testBeanList = new ArrayList<Student>();
20. Student testBean = new Student();
21. );
22. testBean.setStudentName("552");
23. testBeanList.add(testBean);
24. //Gson gsonList = new Gson();
25. Type type = new TypeToken<List<Student>>(){}.getType();  //指定集合对象属性
26. String beanListToJson = gson.toJson(testBeanList, type);
27. System.out.println(beanListToJson); //[{"studentName":"552","studentId":555}]
28. //集合string转对象list
29. List<Student> testBeanListFromJson = gson.fromJson(beanListToJson, type);
30. System.out.println(testBeanListFromJson); //[555:552]
31. //4、集合如果不指定类型 默认为String
32. List<String> testList = new ArrayList<String>();
33. testList.add("first");
34. testList.add("second");
35. String listToJson = gson.toJson(testList);
36. System.out.println(listToJson); //["first","second"]
37. //5、集合字符串转回来需要指定类型
38. List<String> testList2 = (List<String>) gson.fromJson(listToJson,
39. new TypeToken<List<String>>() {
40. }.getType());
41. System.out.println(testList2);
42. //6、 将HashMap字符串转换为 JSON
43. Map<String, String> testMap = new HashMap<String, String>();
44. testMap.put("id", "id.first");
45. testMap.put("name", "name.second");
46. String mapToJson = gson.toJson(testMap);
47. System.out.println(mapToJson); //{"id":"id.first","name":"name.second"}
48. //7、stringMap转对象
49. Map<String, String> userMap2 = (Map<String, String>) gson.fromJson(mapToJson,
50. new TypeToken<Map<String, String>>() {
51. }.getType());
52. System.out.println(userMap2); //{id=id.first, name=name.second}
53. //8、对象含有普通对象、集合、map情况
54. Student user1 = new Student();
55. );
56. user1.setStudentName("张三");
57. Student user3 = new Student();
58. );
59. user3.setStudentName("李四");
60. Map<String, Student> userMap = new HashMap<String, Student>();
61. userMap.put("user1", user1);
62. userMap.put("user3", user3);
63. List<Student> userList = new ArrayList<Student>();
64. userList.add(user1);
65. userList.add(user3);
66. Teacher groupBean = new Teacher();
67. groupBean.setStudent(user1);
68. groupBean.setStus(userList);
69. groupBean.setMap((HashMap)userMap);
70. //groupBean.setUserList(userList);
71. Gson gsonGroup = new Gson();
72. String sGroupBean = gsonGroup.toJson(groupBean, new TypeToken<Teacher>() {
73. }.getType());
74. System.out.println(sGroupBean);
75. /*{"stus":[{"studentName":"张三","studentId":1001},{"studentName":"李四","studentId":1002}],"student":{"studentName":"张三","studentId":1001},"map":{"user3":{"studentName":"李四","studentId":1002},"user1":{"studentName":"张三","studentId":1001}},"id":0,"age":0}*/

1. //9、复杂对象string转对象
2. Teacher groupBean2 = (Teacher) gson.fromJson(sGroupBean,
3. new TypeToken<Teacher>() {
4. }.getType());
5. System.out.println(groupBean2);

1. package com.andtools;
2. import com.google.gson.annotations.Expose;
3. public class Student {
4. @Expose
5. private String studentName;
6. @Expose
7. private int studentId;
8. public Student(){}
9. public Student(int studentId,String studentName){
10. this.setStudentId(studentId);
11. this.setStudentName(studentName);
12. }
13. public String toString(){
14. return this.getStudentId() + ":" + this.getStudentName();
15. }
16. public String getStudentName() {
17. return studentName;
18. }
19. public void setStudentName(String studentName) {
20. this.studentName = studentName;
21. }
22. public int getStudentId() {
23. return studentId;
24. }
25. public void setStudentId(int studentId) {
26. this.studentId = studentId;
27. }
28. }

1. package com.andtools;
2. import java.util.HashMap;
3. import java.util.List;
4. import java.util.Map;
5. import com.google.gson.annotations.Expose;
6. public class Teacher {
7. @Expose
8. private int id;
9. @Expose
10. private String name;
11. @Expose
12. private int age;
13. @Expose
14. private Student student;
15. @Expose
16. private List stus;
17. @Expose
18. private HashMap map;
19. public String toString(){
20. return this.getId()+":"+this.getName()+":"+this.getAge() +":"+ this.getStudent().toString() + ":" + this.getStus() + ":" + this.getMap();
21. }
22. public int getId() {
23. return id;
24. }
25. public void setId(int id) {
26. this.id = id;
27. }
28. public String getName() {
29. return name;
30. }
31. public void setName(String name) {
32. this.name = name;
33. }
34. public int getAge() {
35. return age;
36. }
37. public void setAge(int age) {
38. this.age = age;
39. }
40. public Student getStudent() {
41. return student;
42. }
43. public void setStudent(Student student) {
44. this.student = student;
45. }
46. public List getStus() {
47. return stus;
48. }
49. public void setStus(List stus) {
50. this.stus = stus;
51. }
52. public HashMap getMap() {
53. return map;
54. }
55. public void setMap(HashMap map) {
56. this.map = map;
57. }
58. }